Field of the Invention
The present invention relates to a fixing apparatus and an image forming apparatus.
Description of the Related Art
Conventionally, in an electrophotographic system image forming apparatus, a fixing apparatus has been used for fixing by heating and pressurizing color material (toner) transferred onto a sheet from a photo-conductor drum or an intermediate transfer belt. In recent years, energy saving is demanded in the image forming apparatus, and, for the purpose of improving heating efficiency in the fixing apparatus, a fixing apparatus has been devised in which a heat radiation suppression member such as a reflecting member or a heat insulating member is arranged in the periphery of a heating member for suppressing heat radiation from the heating member (JP 9-101700 A).
In the fixing apparatus, there is a case in which separation failure of the sheet from the heating member occurs. Methods have been performed for this case, such as a method for separating the sheet by a separation claw mechanically, or a method for separating the sheet by blowing air between the sheet and the heating member.
However, it is difficult to avoid the separation failure completely, and in rare cases the sheet is conveyed while being in close contact with the heating member, and may cause a jam. As illustrated in FIG. 11, in a fixing apparatus 360 in which a heat radiation suppression member 370 is provided, since the heat radiation suppression member 370 is installed to cover the outer circumferential surface of a heating member 361, there has been a case in which a sheet P enters between the heating member 361 and the heat radiation suppression member 370 when the jam is caused.
In this case, there has been a possibility that damage and contamination occur in the heat radiation suppression member 370 by scraping and rubbing between the sheet P and the heat radiation suppression member 370. In particular, in the reflecting member, heat radiation suppressing effect is degraded; for example, specularity is degraded by receiving damage to the inner surface, or reflectivity is degraded by adhesion of the toner to the inner surface. In a case in which the heat radiation suppression member 370 and a part of the sheet P are in contact and fixed with each other, when the heating member 361 is damaged by scraping and rubbing between the sheet P and the heating member 361, it has been a cause of image quality degradation.
In a state in which the heating member 361 is covered by the heat radiation suppression member 370, work for removing the sheet P jammed is difficult, and workability has been poor at the time of jam processing, in comparison with a case in which there is no heat radiation suppression member 370. Since the processing is not only simply difficult to eject the sheet P jammed in a narrow space, but also deforms the sheet P during moving in the narrow space, a possibility of damaging a peripheral member when the sheet P is removed also has been high.